Safety appliances for mine locomotives



E. C. WHITFIELD SAFETY APPLIANCES FOR MINE LOCOMOTIVES 3 She'ets-Sheet 1 Jan. 15, 1957 Filed June 22, 1954 ATTORNEYS Jan. 15, 1957 E. c. WHITFIELD SAFETY APPLIANCES FOR MINE LOCOMOTIVES 3 Sheets-Sheet 2 Filed June 22, 1954 INVENTOR idwzdfiihlfie/d ATTORNEYS Jan. 15, 1957 E. c. WHITFIELD 2,777,917

SAFETY APPLIANCES x02 MINE LOCOMOTIVES Filed June 22, 1954 3 SheetsSheet 5 I N VENTOR ATTORNEYS SAFETY APPLIANCES FOR MINE LOCOMOTIVES Edward C. Whitfield, Kitts, Ky., assignor of one-third to Jean Cameron Whitfield and one-third to Augustus 1C. Whitfield, Kitts, Ky.

Application June 22, 1954, Serial No. 438,495 10 Claims. (Cl. zoo-115.5

The present invention relates in general to safety accessories in theelectrical supply assembly for mine locomotives and the like, and more particularly to means for reducing the occurrence of electrical discharges in the trailing cable or electrical supply components of a mine locomotive between the locomotive and the fixed trolley wire from which the current is drawn.

Heretofore, safety applicances such as fuses, circuit breakers and the like have been provided in mine locomotives and similar high current electrical mine machinery used in mines to open the electrical circuit in the event short circuits or abnormally high current-drawing defects occur in the Working parts of the locomotives. Conventionally, the fuses or circuit breakers are located in or directly adjacent to the locomotives at or beyond the locomotive junction box, to open the circuit and prevent breakdowns within the locomotive from producing spark discharges which might ignite the combustible or explosive atmosphere present in coal mines.

It has been found however that many such dischargeproducing break-downs occur in the electrical supply as sembly or trailing cable between the overhead trolley wire from which the locomotive supply current is drawn and the locomotive junction box or body, without open-circuiting the fuses or circuit breakers located on the locomotive. To alleviate this safety problem, the Federal Mining Code now requires that a fuse be installed in the trailing cable or other lead-in cable coupling current from the overhead trolley wire to the mine machinery so as to open circuit the trailing cable near the end coupled to the overhead trolley wire in the event a short circuit occurs in the cable or the electrical machinery so as to prevent ignition of mine fires or release of gases due to overheating of the cable and consumption of the insulation thereon.

To the extent to which fuses have been incorporated in the trailing cables or supply cables of mine locomotives, such fuses have generally been directly inserted in the trailing cable in such a manner that the fuse strip and the connections by which the fuse assembly is joined to the trailing cable bear the full tensional strain imposed on the trailing cable by movement of the locomotive away from the trolley wire. This construction has resulted in a high rate of breakage of the fuse element due solely to mechanical strain and in dangerous electrical :defects resulting from the strain on the anchorages between the fuse terminals and the trailing cable.

An object of the present invention, therefore, is the provision of appliances to be associated with the trailing cable or supply cable of mine locomotive machinery which is of durable and economical construction, and conveniently lends itself to repair or replacement of perishable components and which obviates the above-mentioned disadvantages.

Another object of the present invention is the provision of safety appliances in the electrical supply components coupling current from the overhead trolley wire to mine nited States Patent ice locomotive machinery which effectively prevents spark discharges and gas release which may adversely alfect the safety of workers in the mine.

Another object of the present invention is the provision of a novel fuse assembly for use at the input end of trailing cables for mine locomotives for elfectively open circuiting the trailing cable adjacent the end coupled to the trolley wire upon occurrence of short circuits or overheating in the trailing cable or any mine locomotive machinery components supplied by the same.

Another object of the present invention is the provision of an improved trailing cable fuse assembly for use with mine locomotives having a novel construction for insuring effective safe operation of the fuse throughout the long periods for which such fuses are subjected to severe tensional strains.

Another object of the present invention is the provision of a novel water-tight fuse assembly for trailing cables of mine locomotives constructed in an improved manner to facilitate safe release of gases from the fuse chamber upon blowing of the fuse.

Another object of the present invention is the provision of an improved nip assembly for coupling mine locomotive trailing cables to overhead trolley wires, having novel provisions for withstanding the physical strains applied to such assemblies, and thereby avert electrical breakdowns associated With such assemblies.

Another object of the present invention is the provision of a novel nip assembly for use with the trailing cables of mine locomotives having a fuse unit incorporated therein to protect the user against mine fire or gas release producing defects in the trailing cable or machinery supplied thereby.

Another object of the present invention is the provision of an improved nip assembly for use with the trailing cables of mine locomotives having novel means for the incorporation of scrap materials therein.

Another object of the present invention is the provision of an improved fuse assembly for use with the trailing cables or supply cables of mine machinery having means for interchangeably associating the fuse with trailing cable nips or trolley harps.

Other objects, advantages and capabilities of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings showing only preferred embodiments of the invention.

In the drawings:

Figure 1 is a perspective view of a trailing cable nip and fuse assembly embodying the present invention.

Figure 2 is a longitudinal section view taken along the lines 22 of Figure 1.

Figure 2a is a fragmentary enlargement of Figure 2 illustrating details of the sealing mechanism provided between the casing sleeve and the end plugs.

Figure 3 is a transverse section view illustrating the locking collar arrangement for securing the nip hook to the fuse assembly, taken along the lines 3-3 of Figure 2.

Figure 4 is a transverse section illustrating construction details of the mechanism for anchoring the trailing cable to the fuse, taken along the lines 44 of Figure 2.

Figure 5 is a side elevation of a fuse assembly embodying the present invention assembled on a trolley harp, portions of one of the end plugs of the fuse assembly being broken away to illustrate the anchoring of the trailing cable to the fuse assembly.

Figure 6 is a transverse section view taken along the lines 6-6 of Figure 5.

Figure 7 is a fragmentary longitudinal section view illustrating the mounting of one of the fuse assembly end plugs to the trolley harp, taken along the lines 7-7 of Figure 5.

Figure 8 is a perspective view of a trailing cable nip assembly incorporating another embodiment of the present invention.

Figure 9 is a longitudinal section View taken along the lines 99 of Figure 8.

Figure 10 is a top view of a die and die punch assembly illustrating the manner of use of the same in preparing solid conductors to be used with the terminal anchoring mechanism of the present invention, the die and fragmentary end portions of the solid conductor being shown in section, and;

Figure 11 is a transverse section view taken along the lines li -11 of Figure 10.

Referring to the drawings wherein like reference characters designate corresponding parts throughout the several figures, and particularly to Figures 1 to 4, inclusive, a nip and fuse assembly constructed in accordance with a preferred embodiment of the invention, is generally designated by the reference character 10. The fuse and nip assembly 10 is designed to be joined to the input end of a trailing cable 11 leading to a conventional mine locomotive, and to this end comprises a handle portion generally indicated by the reference character 12 of a con venient size to be gripped by the operator of the mine locomotive and facilitate accurate placement of the nip 13 projecting from the handle portion 12 in or out of hooked relation with the conventional overhead trolley wire.

The handle portion 12 includes a pair of generally cylindrical terminal members 14 and 15 at the rear and front ends respectively of the handle portion 12, which terminal members are preferably turned or otherwise formed of bronze or copper. The adjacent portions of these terminal members 14 and 15 are interconnected and supported by a cylindrical supporting shell 16 of Bakelite or other stress-resistant insulating material having uninterrupted annular end portions surrounding and gripping the adjacent portions of the terminal members 14 and 15 and having an elongated access opening 17 in one wall of the shell 16, preferably located wholly above the medial horizontal longitudinal plane of the shell. The shell 16 is rigidly connected to the terminal members 14 and 15 so as to absorb any tensional strain between the terminal members by means of screws 18 extending through countersunk apertures in the shell 16 and complementary threaded apertures in semicylindrical projections 19 at the adjacent ends of the terminal members 14 and 15 which provide flat terminal seats facing the opening 17 in the shell. Readily replaceable copper washers 20 are disposed over the ends of the mounting screws 18 projecting from the fiat terminal seats and are disposed in contact with each side of the ends of the fuse strip or link 21 which is of conventional commercial form, having apertures or recesses in the opposite ends thereof for intercoupling the fuse strip 21 with the screws 18. Fuse mounting nuts 22 threaded onto the projecting ends of the screws 18 bear against the outermost copper washers 20 to clamp the ends of the fuse strip 21 in intimate contact with the copper washers 20 and the innermost copper washers 21) with the flat terminal seats of the terminal members 14 and 15.

A tight-fitting insulating sleeve 23, preferably formed of asbestos or mica, is fitted over the cylindrical supporting shells 16 to encase the supporting shell and the terminal members 14 and 15 supported thereby.

The portions of the terminal members 14 and 15 pro-- jecting beyond the opposite ends of the insulating sleeve 23 are provided with threads 24 for mounting on these ends of the terminal members end plugs 25 and 26 associated respectively with the rear and front terminal members 14 and 15.

The end plugs 25 and 26 are designed to be threaded onto the terminal members 14 and 15 to a position disposing their adjacent faces in contact with the opposite ends of the insulating sleeve 23, and are provided with annular rabbets 27 in their cylindrical faces extending a substantial distance from adjacent ends of the plug forming seating recesses for the ends of an outer casing sleeve 28 forming the Wall of the handle portion 12. As will be observed in Figure 2a, the shoulders of the annular rabbets 27 are bevelled inwardly as indicated at 29 and the cooperating edges of the casing sleeve 28 are bevelled complementary to the bevelled shoulders 29 for a short distance, as indicated at 30, and then flared away from the bevelled shoulders 29 in divergent relation thereto, as indicated at 31, whereby the adjacent shoulder portions bearing against rubber gaskets 32 disposed therebetween pinch the gasket to form a water-tight seal and permit application of sufficient pressure to the inner surfaces of the rubber gaskets 32 by reason of the diverging surfaces 2') and 31 to permit any gas generated through lowing of the fuse in the fuse chamber to escape before sufficient pressure is built up to explode the casing. This construction, therefore, affords a gas escape valve for the fuse chamber as well as insuring water-tight sealing of the fuse chamber.

An annular groove 33 is provided in the cylindrical wall of each annular rabbet 27 for receiving the ends of Allen set screws 34, or like set screws, carried in annular retaining rings 35 fixed in surrounding relation with opposite ends of the casing sleeve 28 to clamp the casing sleeve 23 to the end plugs 25 and 26 and resist relative movement between the fuse strip 21 and its terminal members 14 and 15 to avoid loosening of the terminal connections with the fuse strip.

To effect secure anchoring of the end of the trailing cable 11 to the nip and fuse assembly 10 so as to withstand the severe strains imposed upon trailing cables, the end portion of the rear terminal member 14, remote from its connection with the fuse strip 21, is provided with a cylindrical anchoring socket 36 opening through the rear end of the terminal member 14 and having a larger diameter medial portion 37 and relatively smaller diameter portions 38 and 39 at the base and entrance respectively of the socket 36. The smaller diameter portion 38 at the base of the anchoring socket 36 forms an annular shoulder for seating an enlarged base flange 40 of a conically shaped divider 41 adjacent the base of the socket 36. The constricted portion 39 at the entrance to the anchoring socket 36 is threaded to receive the complementary threaded portion of an apertured plug 42, the plug 42 having an axial aperture to accommodate the conductive components of the solid conductor or stranded trailing cable 11, and the end plug 25 being provided with an aligned aperture for accommodating the full thickness of the trailing cable 11.

When stranded cable is used for the trailing cable 11, a portion of the insulation is peeled back from the conductor strands to expose the strands and the projecting conductor ends are forced through the aperture in the plug 42 and against the point of the conical divider 41 in axial alignment with the point to spread the ends of the strands into the larger diameter portion 37 of the anchoring socket 36, as illustrated in Figure 2. The plug 42 is then threaded into the threaded smaller diameter portion 39 at the entrance of the socket 36 as far as the plug can be forced, thus bringing the inner face of the plug against the flared strands of the trail-ing cable and jamming them securely between the divider 41 and the larger diameter walls of the socket 36. The group of strands are thus deformed and spread to a larger outer diameter than that of the smaller diameter portion 39 of the socket 36, forming a secure anchorage for the trailing cable 11 which will successfully resist the strains to which it is exposed.

The front terminal member 15 projects beyond the front end plug 26, as indicated at 43, the outer surface having a continuation of the threads 24, and supports a rubber gasket 44 and an arc shield 45 of insulating material adjacent the forward surface of the end plug 26.

The projection 43 is provided with an axial socket 46 of figure 8 cross-section for receiving the end of the nip 13. As shown in the drawings, the nip 13 is an elongated member terminating at its outer end in an integral hook designed to be hooked over an overhead trolley wire to form a conductive connection from which the tnailing cable is trailed as the locomotive runs down a spur track having no overhead wire. The nip 13, which receives great wear and consequently has to be replaced frequently, is in accordance with the present invention formed from a length of standard 4/0 trolley wire, which is of figure 8 cross-section and because it is hard drawn wire is rigid and more durable under this use than circular stock copper wire. Appropriate lengths of such trolley wire can be readily found as scrap material around any coal mine.

An elongated slot 47 is formed through the wall of the projection 43 of the terminal member 15 into the socket 46 to receive a wedge-shaped gander tooth 43. The heel of the gander tooth 48 is disposed against the front face of an annular spanner nut 49 threaded onto the projecting terminal member portion 43 in abutment with the arc shield 45, and a retainer collar 50 surrounding the projection 43 and having an inclined key way 51 receiving the gander tooth 48 is driven toward the arc shield by a lock nut 52 threaded onto the projection 43.

To clamp the free end of the nip 13 in the nip socket 46, the gander tooth 48 is placed in the slot 47 with its teeth projecting toward the nip shank disposed in the socket 416, the collar 56 is slipped over the free end of the projection 43 and along the threads 24 until the surface of the gander tooth 48 projecting out of the slot 47 is seated in the inclined keyway 51 and the lock nut 52 is threaded onto the projection and against the retainer collar 59 as far as it can be forced. The camming action of the inclined keyway 51 on the wedge-shaped gander tooth 48 forces the teeth to take a bite in the nip shank to securely hold the nip seated in the socket 46. When it is desired to remove a nip for replacement the lock nut 52 must be threaded off of the projection 43 and the retainer collar 50 driven toward the free end of the projection .3 out of wedging relation with the gander tooth 48 to free the nip.

Figures and 11 illustrate a mechanism for preparing solid conductors, such as the conductor 53, for use with the anchoring mechanism associated with the anchoring socket 36 described above in connection with stranded conductors. To this end, a pair of complementary die blocks 54 and 55 are provided having a die cavity 56 therein comprising 57 opening through one end of the blocks 54, 55 and extending for a substantial distance into the blocks. The larger diameter portion 57 connects by means of conically tapered wall with an intermediate diameter section 58 which extends for a short distance wially through the block and connects by .a transverse annular shoulder with a smaller diameter portion 59 of the diameter of the solid conductor 53 and continues axially through the opposite end of the die blocks 54, 55.

An exposed portion of the solid conductor 53 projecting beyond the insulation of the trailing cable is placed in the die cavity 56 with the end of the conductor projecting a substantial distance into the larger diameter cavity portion 57. With the blocks 54 and 55 rigidly clamped together in a vice or like support, a die punch 60 having a conical nos'e terminating in a cylindrical portion at its base of a diameter complementary to that of the larger die cavity portion 57 is driven through the exposed entrance of the die cavity portion 57. The first several blows on the die punch 60 tend to spread the conductor in and jam it downwardly to fill the intermediate diameter portion 58 and thereafter prevent further significant axial movement of the conductor 53 in the die cavity. Further driving of the die punch 60 spreads the extreme end portions of the solid conductor a larger diameter cylindrical portion to fill the conically tapered connecting wall portions and the cylindrical wall portions of the larger diameter die cavity portion 57, producing a flared lip of a maximum outer diameter complementary to that of the entrance 39 to the anchoring socket 36. It will be understood that the apertured plug 42 will have been previously fitted onto the solid conductor 53 before its ends are flared in the manner just described, so that when the flared end of the solid conductor 53 is inserted into the anchoring socket 36 with its conical recess fitted over the conical nose of the divider 41, forcing of the plug 42 into the socket entrance 39 and against the flared extremity of the solid conductor 53 will further jam the flared conductor ends into the enlarged diameter portion 37 of the socket 36 to securely anchor the conductor in the socket.

It will be apparent that a blown fuse can be readily replaced in this fuse assembly by rotating the set screws 34 in the retaining ring 35 at the forward end of the casing sleeve 28 to free them from their associated annular grooves 33 and the rear end plug 25 with the casing sleeve 28 still secured thereto rotated to release the rear end plug from the threads on the rear terminal member 14 to permit shifting of these components along the trailing cable 11 a sufiicient distance to expose the opening 17 in the supporting shell 16. The fuse strip 21 i then exposed and the fuse mounting nuts 22 may be unscrewed to permit removal of the copper washers 20 and the fuse strip. If the copper washers have become burned or pitted they can be conveniently replaced, thus eliminating the necessity of refinishing the terminal sets of the terminal members 14 and 15 from time to time.

Figures 5, 6 and 7 disclose an adaptation of the trailing cable fuse assembly to trolley harps for use with free trailing harps of mine locomotives. Referring particularly to Figure 5, the basic components of a conventional trolley harp assembly as generally indicated at 61, are illustrated in conventional mounted position at the trailing end of the cable pole 62 of a mine locomotive. The conventional trolley harp assembly comprises a pole head casting 63 shaped to be fitted over the free end of the pole 62 and bolted thereto, the pole head casting 63 having a pivot bolt socket and mount assembly 64 projecting from the end thereof for receiving a pivot bolt 65 coupled to the conventional trolley harp 66. The trolley harp is an upwardly opening U-shaped bracket having a transverse axle 67 pivotally supporting a contact wheel 68 adapted to ride on the overhead trolley wire.

A boss 69 is usually formed on the other end of the pole head casting 63 projecting from the lower side of the pole, the boss having a flat seat and a threaded aperture or apertures for receiving the threaded shank of a cap screw 70 by which the usual cable clamp casting (not shown) is drawn against the fiat seat of the boss 69 to clamp the end of the trailing cable therebetween. All of the elements above mentioned are formed of electrically conductive material so that the current is conducted through the body of the harp assembly from the overhead trolley wire to the conductor of the trailing cable clamped against the boss 69.

To adapt the fuse assembly of the present invention to such a trolley harp assembly, the cap screw 70 is withdrawn from its threaded socket in the boss 69 and the cable clamp casting is removed. An angle iron bracket 71 is then substituted for the cable clamp casting, one flange of the bracket 71 being apertured to receive the cap. screw 70 and being secured against the fiat seat of theboss 69 by means of the cap screw 70. The other flange of the angle iron bracket 71 which projects downwardlyfrom the boss 69 is provided with a threaded aperture 72 to receive a threaded screw shank 73 which is of theproper diameter and pitch to fit into the threaded entrance portion 39 of the anchoring socket of a rear terminal member 14 of the fuse assembly. A lock nut 74 is.

threaded onto the portion of the threaded screw shank, 73 projecting beyond the depending flange of the bracket.

7 71 to cooperate with the threaded aperture in the flange of the bracket 71 in fixing the threaded shank 73 in the bracket.

In the cable fuse assembly employed with such a trolley harp, generally indicated by the reference character 75, the front terminal member and associated components employed in the fuse assembly of the embodiment illustrated in Figures 1 to 4 is dispensed with and both ends of the fuse assembly are constructed in the same manner as the rear end of the fuse assembly of Figure 1. Accordingly, the fuse strip 21 is supported between two terminal members 14 by means of screws 18, copper washers 2t), and fuse mounting nuts 22, the adjacent ends of the two terminal members 14 being held together in a rigid stress-resistant unit by the cylindrical supporting shell 16, which in turn is surrounded by asbestos or mica insulating sleeve 23 and the outer casing sleeve 23 supported at its ends in the annular rabbets 27 of a pair of end plugs identical to the rear end plug in the first described embodiment. The conical divider 4i and plug 42 associated with the anchoring socket 36 is dispensed within the terminal member 14 disposed nearest the angle iron mounting bracket 71 since the interior of the anchoring socket 36 must be free to receive the end of the threaded screw shank 73 projecting from the bracket 71. When the end plug member 25 on the terminal member 14 is to be disposed nearest the mounting bracket 71 is threaded tightly onto its terminal mem her, the fuse assembly may be shifted toward the mounting bracket '71 to pass the projecting end of the threaded screw shank 73 through the axially aligned aperture in the end plug 25 and into threaded engagement with the threaded entrance portion 39 of the anchoring socket 36 until the associated terminal member 14 and its end plug are rigidly supported against the depending flange of the bracket '71.

The other end of the fuse assembly 75 is identical with the rear end portion of the fuse assembly illustrated and described in connection with Figures to 4 and is manipulated to anchor the end of the trailing cable 11 therein in precisely the same manner described in connection with that embodiment. By this construction, the fuse assembly 75 is rigidly supported on the trolley harp assembly 61 in parallelism with the trolley pole 62 and atfords circuit breaker protection for the trailing cable at a point adjacent the input end of the trailing cable so as to open the electrical circuit in the event of any failure occurring in the trailing cable.

in situations where the mine locomotive operator may be required to spend most of his time throughout the working day nipping the trailing cable onto and off of overhead trolley wires, the combined hip and fuse assembly Ill, illustrated in Figures 1 to 4 may be too heavy and cumbersome to be practical. Accordingly, the modification illustrated in Figures 8 and 9 has been devised which incorporates the advantages of the first described embodiment in regard to the adaptability of the assembly to use with scrap lengths of 4/0 trolley wire for the nip and the securing of the trailing cable and nip anchoring features in a lightweight assembly which can be frequently manipulated Without undue tiring of the operator. To this end, a nip handle assembly, indicated generally by the reference character '76, comprises a handle portion 77 having a terminal member 78 similar in construction to the front terminal member 15 illustrated and described in connection with the first embodiment of Figures 1 to 4 in that it is provided with a forward projection 79 having an axial recess 8-9 of figure 8 crosssection therein for reception of the shank of a nip 13 and an elongated slot 81 for receiving a gander teeth 82 the heel of which butts against a spaner nut 83 threaded onto the projection 79. A retainer collar 34 surrounds the projection 79 and is driven into enveloping relation with the slot 81 with its inclined keyway 85 receiving the inclined-wall portion of. the gander tooth 82 by means of 8 a lock nut 86 likewise threaded onto the projection 79. The recess 80, slot 81, gander tooth 32, spanner nut 83, retainer collar 84 and lock nut as are identical with the socket 46, slot 57, gander tooth 4S, spanner nut 49, retainer collar S t) and lock nut 52 described in connection with the embodiment illustrated in Figures 1 to 4 and coact in the identical manner.

Intermediate the ends of the terminal member 78 is an annular groove 87' for housing a split ring tid. Projecting rearwardly of the groove 7 is a cylindrical projection 35 having an anchoring socket 5%; opening through the rear face thereof for housing a conical divider 9t and having a threaded plug 92 cooperating with a threaded entrance to the socket 9?) for securely anchoring the end of the conductor of a trailing cable ll the anchoring so '56. The anchoring socket 90, conical divider 9i and th r ed ping 9 2 are identical to the anchoring socket 36, conical divider 41 and plug described in connection with the embodiment illustrated in Figures 1 to 4, and operate in the same manner to anchor the trailing cable conductor in the terminal member 7'8.

An outer casing sleeve 93 is adapted to be supported on the terminal member 73 with the inwardly projecting annular shoulder 5 at the forward end of the casing sleeve 13 disposed forwardly of the split ring 88 in the annular groove: 87. An arc shield is supported on the terminal member 73 between the forward edge of the casing sleeve and the spanne t b3, the spanner nut 83 be. lurinl to jam the arc 94- against the casing sleeve 93 and clamp the casing sleeve to the terminal member 78 between the arc shield c. the split ring 35.

An intermediate tubular sleeve $25, terminating in col rged diameter heel 9d and having an axial bore 97 extending therethrough complementary to the rear projection of the terminal member '73, extends coaxially with the casing sleeve 93 and terminal member '78 with its forward portion enveloping the rear terminal member projection and extending between the terminal mem her and the inner surface of the casing sleeve It will be understood that the free end of the trailing cable ii is projected through the axial bore 97 of the tubular sleeve 95 before the end of the trailing cable is anchored to the terminal member 7%, and the tubular sleeve 95 following anchoring of the trailing cable is slipped along the cable to insert the same within the outer casing sleeve 93. The forwardly disposed annular shoulder between the heel 96 and the tubular sleeve 95 is brought into contact with the rear edge of the outer casing sleeve 93 and set screws '98 mounted in a retainer ring 9% adjacent the rear edge of the casing sleeve 93 are projected into annular groove 335 formed in the wall *3 the tubular sleeve adjacent the annular shoulder of the heel to inter lock the tubular sleeve 95 with the casi 1g sleeve To comply with the Federal Mining Code, a trailing cable fuse of the type illustrated and de ibed in connection with Figures 5 to 7, but having the anchoring mechanism in each terminal member, may be inserted in the trailing cable at a point sufiiciently removed from the nip handle assembly 723 to allow the fuse to rest on the locomotive. Under such conditions, the rela. ely light nip handle assembly 76 can be manipulated freely and accurately Without the operator being encumbered With the weight and bulk of the fuse assembly.

While several specific embodiments of the invention have been described, it is apparent that further changes and modifications can be made without departing from the intended scope of the invention as defined in the appended claims.

I claim:

1.. A safety device adapted to be disposed in series circuit relation with a trailing cable for mine locomotives and the like comprising an outer elongated cylindrical casing sleeve, an electrically conductive terminal member coaxially disposed within said casing sleeve, said terminal member having anchoring means in one end thereof comprising an axially disposed socket opening toward the adjacent end of said terminal member, said socket having a constricted threaded entrance, a threaded plug adapted to be received in said constricted entrance and having an aperture therein for receiving the conductive components of a trailing cable therethrough, a conical divider insert disposed in said socket with its apex facing the entrance thereof for spreading the ends of the trailing cable conductive components forced against the same radially of the axis of said conductive components to occupy a diameter greater than that of said constricted entrance for clamping said trailing cable within said socket, and means associated with the opposite end of said terminal member for conductively coupling the same with an overhead trolley wire to supply current therethrough to said trailing cable conductive components.

2. A safety device adapted to be disposed in series circuit relation with a trailing cable for mine locomotives and the like comprising an outer elongated cylindrical casing sleeve, an electrically conductive terminal member coaxially disposed within said casing sleeve, said terminal member having anchoring means in one end thereof comprising an axially disposed socket opening toward one end of said casing sleeve, said socket having a larger diameter medial portion and a smaller diameter threaded entrance portion, a threaded plug adapted to be threaded in said entrance portion and having an aperture therein for receiving therethrough a bundle of strands of a stranded trailing cable, a conical divider insert held in coaxial relation within said socket with its apex facing said entrance portion for spreading said strands radially of the axis of said trailing cable to the maximum diameter of said socket and in cooperation with said plug jam said strands in securely held relation in said socket rearwardly of said entrance portion, and electrically conductive means coupled to the other end of said terminal member for conductively connecting the same with an overhead trolley wire to supply current therethrough to said trailing cable.

3. A safety device adapted to be disposed in series circuit relation with a trailing cable for mine locomotives and the like comprising an outer elongated cylindrical casing sleeve, a hollow cylindrical fuse receptacle coaxially disposed within said casing sleeve for relieving a fuse supported therein of tensional stresses applied to the ends of said receptacle, said receptacle having an access opening in the wall thereof and fixed electrically conductive terminal members forming the end closures thereof, means at the adjacent ends of said terminal members within said receptacle for removably supporting opposite ends of a fuse strip, said terminal members each having an outwardly opening socket therein disposed axially of said receptacle, one of said sockets having a constricted threaded entrance for receiving a threaded plug having an aperture therein for accommodating a trailing cable conductor and a conical divider insert within the socket facing the entrance thereof for expanding the end of a trailing cable conductor forced against the same to the maximum diameter of said socket rearwardly of the constricted entrance thereof and secure said trailing cable conductor within said socket, and means operatively associated with the other terminal member socket for securely anchoring a conductor therein to conductively couple the terminal member anchoring said trailing cable conductor with an overhead trolley wire.

4. A safety device adapted to be disposed in series circuit relation with a trailing cable for mine locomotives and the like comprising an outer elongated cylindrical casing sleeve, a hollow cylindrical fuse receptacle caxial ly disposed within said casing sleeve for relieving a fuse supported therein of tensional stresses applied to the ends of said receptacle, said receptacle having an access opening in the wall thereof and fixed electrically conductive terminal members forming the end closures thereof, means at the adjacent ends of said terminal members for removably supporting-opposite ends ofa fuse strip within said receptacle, at least one of said terminal members having an outwardly opening socket therein disposed axially of said receptacle, said socket having a constricted threaded entrance for receiving a threaded plug, said threaded plug having an aperture therein for receiving the conductor of a trailing cable therethrough, a conical divider insert disposed in said socket facing the entrance thereof for expanding a trailing cable conductor end forced against the same to the maximum diameter of said socket and secure said trailing cable conductor within said socket in conjunction with said plug, insulating end plugs axially removably mounted on said terminal members for supporting said casing sleeve thereon and forming a water-tight enclosure, and means for conductively connecting said terminal members with an overhead trolley wire to supply current therethrough to said trailing cable conductor.

5. A nip holder for trailing cables for mine locomotives and the like comprising a handle portion including an outer elongated cylindrical casing sleeve, a hollow cylindrical fuse receptacle coaxially disposed within said casing sleeve for receiving a fuse supported therein of tensional stresses applied to the ends of said receptacle, said receptacle having an access opening in the wall thereof and fixed electrically conductive terminal members forming the end closure thereof, means at the adjacent ends of said terminal members for removably supporting opposite ends of a fuse strip within said receptacle, at least one of said terminal members having an outwardly opening socket therein disposed axially of said receptacle, said socket having a constricted threaded entrance for receiving a threaded plug, said threaded plug having an aperture therein for receiving the conductor of a trailing cable therethrough, a conical divider insert disposed in said socket facing the entrance thereof for expanding a trailing cable conductor end forced against the same to the maximum diameter of said socket and secure said trailing cable conductor within said socket in conjunction with said plug, the other of said terminal members having a recess opening externally thereof and extending axially of said casing sleeve for receiving the shank of a trolley wire nip, and means for removably securing said nip in said recess.

6. A safety device for trailing cables for mine locomotives and the like comprising a nip holder assembly in cluding a handle portion having an outer elongated casing sleeve of insulating material, an anchoring member disposed coaxially within said casing sleeve and held against relative longitudinal displacement with said casing sleeve, said anchoring member having a socket opening toward one end of said casing sleeve, and means for securely gripping a trailing cable conductor in said socket a trailing cable nip formed of overhead trolley cable of figure 8 cross section and having an elongated shank, an elongated nip mounting member projecting from the other end of said casing sleeve and held against displacement relative to said anchoring member, said nip mounting member having a coaxial recess of figure 8 cross section open through the outer end thereof to receive the shank of said nip and an elongated slot extending longitudinally of said mounting member communicating with said recess and opening through a wall of said member, a wedge shaped clamping member disposed in said elongated slot with an inclined surface thereof projecting from said slot, and having teeth projecting therefrom toward said axial recess to engage the shank of the trolley wire nip inserted in said recess, abutment means holding said wedge-shaped clamping member against movement axially of said mounting member, collar means on said mounting member movable axially thereof and having an inclined surface bearing upon the inclined surface of said wedge-shaped clamping member, and means for shifting said collar means to wedge the teeth of said wedge-shaped arrest? '11 member into the'shank of a nip disposed in said axial recess to retain the nip against withdrawal therefrom.

7. A safety device adapted to be disposed in series circuit relation with a trailing cable for mine locomotives and the like comprising an'outer elongated cylindrical casing sleeve, a hollow cylindrical fuse receptacle coaxiallydisposed within said casing sleeve for relieving a fuse supported therein of tensional stresses applied to the ends of said receptacle, said receptacle having an access opening in the wall thereof and fixed electrically conductive terminal members forming the enclosures thereof, means at the adjacent ends of said terminal members within said receptacle for removably supporting opposite ends of a fuse strip, said terminal members each having an outwardly opening socket therein disposed axially of said receptacle, one of said sockets having a constricted threaded entrance for receiving a threaded plug having an aperture therein for accommodating a trailing cable conductor and a conical divider insert within the socket facing the entrance thereof for expanding the end of a trailing cable conductor forced against the same to the maximum diameter of said socket rearwardly of the constricted entrance thereof to secure said trailing cable conductor within said socket, a trolley wire nip having a shank thereof disposed in the socket of the other terminal member, said terminal members having an elongated axially aligned slot communicating with its socket and opening through a wall of said terminal member, a wedge disposed in said elongated slot for movement transversely of the axis of said terminal member having an inclined surface projecting externally of said slot, and teeth projecting toward the socket therein, means holding said wedge against axial movement, and collar means on said other terminal member movable axially thereof and having an inclined cam surface bearing upon the external inclined surface of said wedge for locking the teeth of said wedge into the shank of said trolley wire nip to hold the same against withdrawal.

8. A nip assembly for trailing cables for mine locomotives and the like comprising a handle portion having an outer cylindrical casing sleeve of insulating material, a generally cylindrical conductive terminal member disposed coaxially within said casing sleeve, means connecting said terminal member with said casing sleeve to prevent relative longitudinal displacement thereof, said terminal member having a socket opening toward one end of said casing sleeve and disposed axially of the same, sai socket having a larger diameter medial portion and a smaller diameter threaded entrance portion, a threaded plug adapted to be threaded in said entrance portion and having an aperture therein for receiving a trailing cable conductor therethrough, a conical divider insert held in coaxial relation within said socket with its apex facing said entrance portion for spreading said conductor radially of the axis of said trailing cable to the maximum diameter of said socket and in cooperation with said plug jam said conductor in securely held relation within said socket, said trailing cable when anchored in said socket extending through said casing sleeve and a major portion of the length of said casing sleeve, a reinforcing rigid tubular member having an aperture accommodating said trailing cable throughout the extent of said trailing cable within said casing sleeve, means securing said reinforcing tubular member at one end in surrounding relation with the socketed portion of said terminal member and at the other end with said casing sleeve, said terminal member having a projection extending through an end of said casing sleeve oppositely disposed with relation to said trailing cable, said projection having an axial recess opening in the end thereof for receiving the shank of a trolley wire nip, and clamping means in said projection for rigidly securing said trolley wire nip in said recess.

9. A safety device adapted to be disposed in series circuit relation with a trailing cable for mine locomotives and the like comprising an outer elongated cylindrical casing sleeve, a holiow cylindrical fuse receptacle coaxially disposed within said casing sleeve having an access opening in the wall thereof and fixed electrically conductive terminal members forming the end closures thereof, means at the adjacent ends of said terminal members within said receptacle for removably supporting opposite ends of a fuse strip, said terminal members each having means exposed externally of said casing sleeve for anchoring the ends of electrical conductors therein, cylindrical end plugs of insulating material removably supported on said terminal members, each having apertures therein for the reception of said conductors, said end plugs having annular rabbets disposed to receive the opposite edges of said casing sleeve, means securing said casing sleeve to said end plugs, each of said rabbets having an annular shoulder confronting an annular edge of said casing sleeve, a resilient gasket disposed between each of said confronting annular shoulders and edges, each of said annular shoulders being inclined toward the bases of said rabbets and away from their confronting edges and their confronting edges each having an outer annular portion inclined parallel to said annular shoulders and an inner annular portion inclined away from said annular shoulders to form with the resilient gasket disposed therebetween valve means for releasing gases generated in said fuse receptacle upon blowing of a fuse prior to accumulation of sufficient pressure to spread said casing sleeve.

10. A safety device adapted to be disposed in series circuit relation with a trailing cable for mine locomotives and the like comprising an outer elongated cylindrical casing sleeve, an electrically conductive elongated terminal unit coaxially disposed Within said casing sleeve, said terminal unit having anchoring means in the 0pposite ends thereof each comprising an axially disposed socket opening toward the adjacent end of said terminal unit said socket having a constricted threaded entrance and an inwardly disposed larger diameter portion, the inner end wall of said socket having a cylindrical recess therein coaxial with the axis of said socket of a diameter at least as small as that of said constricted entrance, a threaded plug adapted to be received in said constricted entrance and having an aperture therein for receiving therethrough the end of an electrical conductor which is capable ofbcing flared radially outwardly from its longi tudinal medial axis, a conical divider insert disposed in the enlarged diameter portion of said socket with its base removably seated in said cylindrical recess in the end wall of said socket with its apex racing the entrance thereof for spreading the end of the electrical conductor forced against the same radially of the axis of the conductor to flare the same to a diameter greater than that of said con stricted entrance for clamping said conductor end within said enlarged diameter portion of said socket, and means associated with the anchoring means at one end of said terminal unit for conductively coupling the same with an overhead trolley wire to supply current thercthrough to the electrical conductor coupled to the other of said anchoring means.

References Cited in the file of this patent UNITED STATES PATENTS (1st addition to No. 468,084) 

